It is very rare to contract vibrio. Sure, it happens and there's a story or two every year about it but out of the hundreds of thousands of beach visitors annually, there are only a handful of cases. So, unless you have an open wound while at the beach, dousing yourself in hibiclens or peroxide is overkill. As previously stated, most cases where it is contracted is in the backwaters of bays, where the water becomes stagnant because it isn't getting recharged.
Regarding the shark bites yesterday, look at the water condition. Murky, dirty water, which is what you see when many shark attacks occur. My money is on a bull shark being the culprit.
People think I'm an idiot or something, because all I do is cut lawns for a living.